A photolithography technique has been heretofore known as one of microfabrication techniques. In the photolithography technique, a negative photosensitive resin is exposed and developed to form a pattern and a structure. This technique is widely used in manufacture applications such as a semiconductor integrated circuit, a semiconductor exposing mask, and various MEMS (Micro ElectroMechanical Systems). The technique is applied to manufacture a nozzle of a liquid discharge head, as an example of the manufacture applications of the MEMS. For example, a stepper having an i-line as a light source is widely used as an exposing device. In this technical field, recently, manufacture of a more complex and high-definition structure object has been required. Therefore, a negative photosensitive resin composition exhibiting high photosensitivity and molding accuracy to light from a light source has been required.
Japanese Patent Application Laid-Open No. 2008-256980 discloses a photosensitive resin composition containing a polyfunctional epoxy resin and a photoacid generator, as an example of the negative photosensitive resin compositions. An acid derived from an anion portion structure of the photoacid generator used herein has a strong acid strength, and improve sensitivity of the photosensitive resin composition compared with hexafluoroantimonic acid.
US 2004/0072107 A1 and US 2006/0071971 A1 disclose a liquid discharge head and a manufacturing method thereof as an example of the liquid discharge heads. The liquid discharge head heats a heating resistor to foam ink, thereby discharging ink droplets. In the manufacture of the liquid discharge head, high temperature processing is conducted at 200° C. in a curing process of a photosensitive resin composition.